Temperature effects on solutions of vinblastine-induced polymers assembled from brine shrimp (Artemia) tubulin

Purified Artemia tubulin in the presence of neural microtubule-associated proteins and vinblastine, or with vinblastine alone, forms extensive coils. Reduction in temperature of a coil-containing solution to 4 degrees C causes an increase in turbidity, which returns to previous levels once the solution is warmed. Examination of negatively stained samples indicates that the turbidity fluctuations are not accompanied by a pronounced change in coil structure nor by increased polymer formation. Bovine neural tubulin responds in the same way as Artemia tubulin to vinblastine and temperature. An interesting novel response to vinblastine, shared by tubulins from phylogenetically distinct organisms, is illustrated by our results.